Color photography



W. FRIESE-GREENE.

COLOR PHOTOGRAPHY.

APPLICATION FILED IAII.`3I,'I92I.

Pandsept. 20,1921.

)VM im,

UNITED STATES PATENT OFFICE.

WILLIAM IRIESE-GBEENE, 0F LNDDN, ENGLAND, ASSIGNOR T0 COLOUR PHOTOG-MPHY LIMITED, 0F LONDON, ENGLAND.

COLOR PHOTOGRAPHY.

Specication ot-Letters Patent. Patented Sept, 20, 1921,

Original application illed July 8, 1919, Serial No.` 309,455. Dividedand this application led January 31, 1921. Serial No. 441,495.

To all /wwm it may concern.'

Be it known that I, WILLIAM FRmsE- GREENE, a subject of the King ofEngland, residing in London, England, have invented certain new anduseful Improvements in Color Photography, of which the following is aspecification.

This invention is for improvements in or relating to color photography,and has for one of its ob'ects to improve the production of colored potographs whether for use as transparencies or for mounting on opaquemounts The invention is applicable both to the photography in colors ofstill life and animate or inanimate objects and to'cinematography, andrenders such color photography morefsimple in operat1on.

Another part of the invention relates to an improvedI process of colorphotography in which two sensitized surfaces are simultaneously orsubstantially simultaneously exposed the one through a color filter andthe other without such filter.

A specific object of the invention is to improve color photographyprocesses based upon the employment of two colors whereby anapproximation to natural color effects 1s obtained. In particular theinvention alms at improvin two-color cinematography.

These an other objects and features of the invention will now bedescribed in detail, with the aid of the accompanying drawin inwhichsiguresl and 2 diagrammatically illustrate two arrangements of thesensitized surfaces upon which the original exposures are made; and

Fig. 3 illustrates diagrammatically two superimposed surfaces bearingthe resultant photographic images.

The color sensitizer according to the present invention comprisespinacyanol, pinaverdol, pinachrome, lavazine sometimes avazin orlavasine) and ammoniamixed with Water, and preferably the proportionsemployed are as follows Pinacyanol 2grains Pinaverdol Ggrains Pinachrome.12 grains Flavazine 4grains Ammonia (.880) 4ozs.

Distilled water 65 pints In making up the sensitizer therst fouringredients in the quantities stated are preferably placed in 10 ozs. ofboiling alcohol and stirred for say 10 minutes until thoroughlydissolved, after which 65 pints of distilled water ma be added at atemperature of about 70 ahr. and then the v4: ozs. of ammonia added.'The film or plate to be color-sensitized is immersed in th1s mixture forabout 5 minutes and kept constantly in movement. The drying should beeffected quickly at a temperatureof about 75 Fahr.

The light-sensitive surface of a photographic .plate or iilmcolor-sensitized by this formula is panchromatic, and such plaines orfilms may be used for any urpose .for which panchromatic plates or lmsare suitable, givlng very eilicient results and satisfactory coloreffects. According to the present invention, however, panchromaticplates or films color-sensitized by the above formula, are used inimproving color-photographyon the two-color rinciple.

The ingredients detai ed above are referred to by the -names commonlygiven to them in the chemical and color photographicindustry. It will beunderstood, however, that pinacyanol (sometimes known as sensitol red)isobtained by treating quinaldinium salts with formaldehyde followed byalkali.

Pinaverdol is p-toluquinaldinquinoliniummethylc aninbromid.

Pinac rome is p-thoXyquinaldin-p-methox quinoline-ethylcyaninebromid.

lavazine is one of the few important dyes belonging to the small classof pyrazolone dye-stuffs and is a dye similar to tartrazin. f

In the photographic process according to the present invention, the twosuperimposed light-senstitive surfaces 1 and 2, Fig. 1, are supported byseparate backngs of glass or transparent films 3 and 4, respectively, ascommonly employed in photographic proc- 'esses or, as shown in Fig. 2,they are both erably on separate backings placed face-toface, as shownin Fig. 1, and are simultaneously ex osed in the camera, the frontsurface 1, t at is to lsay the one which is first acted u on by theincident light being prepared rom the ordinary non-color-senslsitized ornot, is acted upon by the incident light without the interposition ofany colorscreen or filter and, in the case of a nonspeciall -sensitizedsurface, will be particularly a ected by light from the blue end of thespectrum and only slightly or comparatively slightly by light from thered end of the spectrum. The red rays, however, together with some greenand blue, will pass through the front surface and will operate upon therear surface which is specially sensitized as above described.

Color-images can then be produced from the two negatives thus-obtainedwhether on separate backings or on a single backing, either by toning orstaining the negative images themselves or positive images obtainedtherefrom, or in any other suitable way. The colors preferably used are,say, orange-pink or some other color toward the red end of the spectrumand blue-green or some other color toward the blue end of the spectrum.Whether the negatives themselves are being colored or whether an opaquepositive Yis in question, the negative image nearer the lens or thepositive image produced from it, will be colored orangepink and theother negative image or the corresponding positive image will be coloredblue-green.

Where two transparentpositives are to be used to ether, for example forcinematograph lms as pictures or transparencies viewed by transmittedlight or as lantern slides the positive image produced from the negativethat was nearer the lens will be colored orange-pink and the otherbluegreen.

In either case the coloring may be effected in a toning bath or bystaining applied to the negative or positive as the case may be. Aftercoloring, the negatives, such as 6 and 7 Fig. 3, or positives aremounted in register on a single backing 8 or, in the case ofcinematograph films, they are suitable for simultaneous individualexposure to be superimposed in register on the screen onto which theyare projected.

Any suitable means may be employed for toning or staining the twonegatives or positives, the colors being adjusted t0 the coloreffectsdesired in accordance with the subject under treatment.

The marked difference of color values ohtained by the use of the specialsensitizer aforesaid, leaves room for considerable manipulation of thecolors in the toningor staining-bath, so that the depth of color ofeither plate may be modified as requiredto obtain a proper balanceaccording to the color effects desired and according to the subjectunder treatment. This balance can only be judged by the operator foreach Subject, and will depend largely upon individual taste, but thefact that 'a large difference of color value is obtained by means ofthis invention leaves scope for the desired I manipulation.

For quick work, the employment of two panchromatic plates or filmsprepared with the special sensitizer aforesaid is preferred.

If one print is on paper and the other on a transparent material, thetransparent print will be superimposed upon the opaque print in registertherewith in the relatlve positions indicated in Fig. 3, and the two maythen be mounted in any desired manner. With practice a coloredphotographic print having considerable resemblance to nature can thus beobtained.

Although plates, such as 3, 4 and 5, have been referred to, obviouslyfilms may be employed in their. place, and also the nished product maybe made as a transparency suitable say for cinematograph projection, butilizing transparent material for both prints.

In applying the invention to cinematography,l the celluloid portion ofthe films may be of ordinary manufacture but the sensitizing materialfor one or both of the films should preferably be made as aforesaid. Thetwo films can be run simultaneously through the camera for exposure, as,for example, with the sensitized surfaces in contact as shown in Fig. 1,and the subsequent treatment will be the same as has already beendescribed with reference to plates. The final product, however, will bea transparency, with the parts in the relative positions of Fig. 3.Instead of toning the final product to different colors, the film may bestained the desired colors on opposite sides though, for the productionof ordinary colored photographs the process as first described may beused. For cinematograph work the staining is possible because of thepersistency of vision and the strong light behind the film.

The present application is a division of my application Serial No.309,455, led July invention and desire atent 1s:-

What I claim as m to secure by Letters 1. A color-'photography process,compris,

ing simultaneously exposlng two superimposed sensitized surfaces whereofat least one is color-sensitized with pinacyanol, pinaverdol,pinachrome, flavazine and ammonia mixed with water.

2. A color-photography process comprising making a simultaneous exposureof two superimposed sensitized surfacesl of which the one remote fromthe object is colorsensitized withpinacyanol, pinaverdol, pinachrome,iiavazine and ammonia mixed with l Water. 3. A color-photography processcompriscolor-sensitized with pinac anol,pinaverdo1 pinachrome, avazinean ammonia. mixe with water.

4. A color-photography process' .comprising simultaneously exposmgwithout a light lter or other color-screen two superimposed sensitizedsurfaces placed face-to-fac'e of which the one nearer the incident lightis an ordinary-non-color sensitized surface and he other 1s apanchromatic sensitized surace.

In testimon whereof I aiix m si nature.

WI IAM FRIESE-G E NE.

